A tunable topological insulator in the spin helical Dirac transport regime

D. Hsieh, Y. Xia, D. Qian, L. Wray, J. H. Dil, F. Meier, J. Osterwalder, L. Patthey, J. G. Checkelsky, N. P. Ong, A. V. Fedorov, H. Lin, A. Bansil, D. Grauer, Y. S. Hor, R. J. Cava, M. Z. Hasan

    Research output: Contribution to journalArticle

    Abstract

    Helical Dirac fermions - charge carriers that behave as massless relativistic particles with an intrinsic angular momentum (spin) locked to its translational momentum - are proposed to be the key to realizing fundamentally new phenomena in condensed matter physics. Prominent examples include the anomalous quantization of magneto-electric coupling, half-fermion states that are their own antiparticle, and charge fractionalization in a Bose-Einstein condensate, all of which are not possible with conventional Dirac fermions of the graphene variety. Helical Dirac fermions have so far remained elusive owing to the lack of necessary spin-sensitive measurements and because such fermions are forbidden to exist in conventional materials harbouring relativistic electrons, such as graphene or bismuth. It has recently been proposed that helical Dirac fermions may exist at the edges of certain types of topologically ordered insulators - materials with a bulk insulating gap of spin-orbit origin and surface states protected against scattering by time-reversal symmetry - and that their peculiar properties may be accessed provided the insulator is tuned into the so-called topological transport regime. However, helical Dirac fermions have not been observed in existing topological insulators. Here we report the realization and characterization of a tunable topological insulator in a bismuth-based class of material by combining spin-imaging and momentum-resolved spectroscopies, bulk charge compensation, Hall transport measurements and surface quantum control. Our results reveal a spin-momentum locked Dirac cone carrying a non-trivial Berry's phase that is nearly 100 per cent spin-polarized, which exhibits a tunable topological fermion density in the vicinity of the Kramers point and can be driven to the long-sought topological spin transport regime. The observed topological nodal state is shown to be protected even up to 300 K. Our demonstration of room-temperature topological order and non-trivial spin-texture in stoichiometric Bi2Se3.Mx (Mx indicates surface doping or gating control) paves the way for future graphene-like studies of topological insulators, and applications of the observed spin-polarized edge channels in spintronic and computing technologies possibly at room temperature.

    Original languageEnglish (US)
    Pages (from-to)1101-1105
    Number of pages5
    JournalNature
    Volume460
    Issue number7259
    DOIs
    StatePublished - Aug 27 2009

    Fingerprint

    Graphite
    Bismuth
    Temperature
    Physics
    Orbit
    Fruit
    Spectrum Analysis
    Electrons
    Technology

    ASJC Scopus subject areas

    • General

    Cite this

    Hsieh, D., Xia, Y., Qian, D., Wray, L., Dil, J. H., Meier, F., ... Hasan, M. Z. (2009). A tunable topological insulator in the spin helical Dirac transport regime. Nature, 460(7259), 1101-1105. https://doi.org/10.1038/nature08234

    A tunable topological insulator in the spin helical Dirac transport regime. / Hsieh, D.; Xia, Y.; Qian, D.; Wray, L.; Dil, J. H.; Meier, F.; Osterwalder, J.; Patthey, L.; Checkelsky, J. G.; Ong, N. P.; Fedorov, A. V.; Lin, H.; Bansil, A.; Grauer, D.; Hor, Y. S.; Cava, R. J.; Hasan, M. Z.

    In: Nature, Vol. 460, No. 7259, 27.08.2009, p. 1101-1105.

    Research output: Contribution to journalArticle

    Hsieh, D, Xia, Y, Qian, D, Wray, L, Dil, JH, Meier, F, Osterwalder, J, Patthey, L, Checkelsky, JG, Ong, NP, Fedorov, AV, Lin, H, Bansil, A, Grauer, D, Hor, YS, Cava, RJ & Hasan, MZ 2009, 'A tunable topological insulator in the spin helical Dirac transport regime', Nature, vol. 460, no. 7259, pp. 1101-1105. https://doi.org/10.1038/nature08234
    Hsieh D, Xia Y, Qian D, Wray L, Dil JH, Meier F et al. A tunable topological insulator in the spin helical Dirac transport regime. Nature. 2009 Aug 27;460(7259):1101-1105. https://doi.org/10.1038/nature08234
    Hsieh, D. ; Xia, Y. ; Qian, D. ; Wray, L. ; Dil, J. H. ; Meier, F. ; Osterwalder, J. ; Patthey, L. ; Checkelsky, J. G. ; Ong, N. P. ; Fedorov, A. V. ; Lin, H. ; Bansil, A. ; Grauer, D. ; Hor, Y. S. ; Cava, R. J. ; Hasan, M. Z. / A tunable topological insulator in the spin helical Dirac transport regime. In: Nature. 2009 ; Vol. 460, No. 7259. pp. 1101-1105.
    @article{8f09147a8a0c46c5b989913d264919c2,
    title = "A tunable topological insulator in the spin helical Dirac transport regime",
    abstract = "Helical Dirac fermions - charge carriers that behave as massless relativistic particles with an intrinsic angular momentum (spin) locked to its translational momentum - are proposed to be the key to realizing fundamentally new phenomena in condensed matter physics. Prominent examples include the anomalous quantization of magneto-electric coupling, half-fermion states that are their own antiparticle, and charge fractionalization in a Bose-Einstein condensate, all of which are not possible with conventional Dirac fermions of the graphene variety. Helical Dirac fermions have so far remained elusive owing to the lack of necessary spin-sensitive measurements and because such fermions are forbidden to exist in conventional materials harbouring relativistic electrons, such as graphene or bismuth. It has recently been proposed that helical Dirac fermions may exist at the edges of certain types of topologically ordered insulators - materials with a bulk insulating gap of spin-orbit origin and surface states protected against scattering by time-reversal symmetry - and that their peculiar properties may be accessed provided the insulator is tuned into the so-called topological transport regime. However, helical Dirac fermions have not been observed in existing topological insulators. Here we report the realization and characterization of a tunable topological insulator in a bismuth-based class of material by combining spin-imaging and momentum-resolved spectroscopies, bulk charge compensation, Hall transport measurements and surface quantum control. Our results reveal a spin-momentum locked Dirac cone carrying a non-trivial Berry's phase that is nearly 100 per cent spin-polarized, which exhibits a tunable topological fermion density in the vicinity of the Kramers point and can be driven to the long-sought topological spin transport regime. The observed topological nodal state is shown to be protected even up to 300 K. Our demonstration of room-temperature topological order and non-trivial spin-texture in stoichiometric Bi2Se3.Mx (Mx indicates surface doping or gating control) paves the way for future graphene-like studies of topological insulators, and applications of the observed spin-polarized edge channels in spintronic and computing technologies possibly at room temperature.",
    author = "D. Hsieh and Y. Xia and D. Qian and L. Wray and Dil, {J. H.} and F. Meier and J. Osterwalder and L. Patthey and Checkelsky, {J. G.} and Ong, {N. P.} and Fedorov, {A. V.} and H. Lin and A. Bansil and D. Grauer and Hor, {Y. S.} and Cava, {R. J.} and Hasan, {M. Z.}",
    year = "2009",
    month = "8",
    day = "27",
    doi = "10.1038/nature08234",
    language = "English (US)",
    volume = "460",
    pages = "1101--1105",
    journal = "Nature Cell Biology",
    issn = "1465-7392",
    publisher = "Nature Publishing Group",
    number = "7259",

    }

    TY - JOUR

    T1 - A tunable topological insulator in the spin helical Dirac transport regime

    AU - Hsieh, D.

    AU - Xia, Y.

    AU - Qian, D.

    AU - Wray, L.

    AU - Dil, J. H.

    AU - Meier, F.

    AU - Osterwalder, J.

    AU - Patthey, L.

    AU - Checkelsky, J. G.

    AU - Ong, N. P.

    AU - Fedorov, A. V.

    AU - Lin, H.

    AU - Bansil, A.

    AU - Grauer, D.

    AU - Hor, Y. S.

    AU - Cava, R. J.

    AU - Hasan, M. Z.

    PY - 2009/8/27

    Y1 - 2009/8/27

    N2 - Helical Dirac fermions - charge carriers that behave as massless relativistic particles with an intrinsic angular momentum (spin) locked to its translational momentum - are proposed to be the key to realizing fundamentally new phenomena in condensed matter physics. Prominent examples include the anomalous quantization of magneto-electric coupling, half-fermion states that are their own antiparticle, and charge fractionalization in a Bose-Einstein condensate, all of which are not possible with conventional Dirac fermions of the graphene variety. Helical Dirac fermions have so far remained elusive owing to the lack of necessary spin-sensitive measurements and because such fermions are forbidden to exist in conventional materials harbouring relativistic electrons, such as graphene or bismuth. It has recently been proposed that helical Dirac fermions may exist at the edges of certain types of topologically ordered insulators - materials with a bulk insulating gap of spin-orbit origin and surface states protected against scattering by time-reversal symmetry - and that their peculiar properties may be accessed provided the insulator is tuned into the so-called topological transport regime. However, helical Dirac fermions have not been observed in existing topological insulators. Here we report the realization and characterization of a tunable topological insulator in a bismuth-based class of material by combining spin-imaging and momentum-resolved spectroscopies, bulk charge compensation, Hall transport measurements and surface quantum control. Our results reveal a spin-momentum locked Dirac cone carrying a non-trivial Berry's phase that is nearly 100 per cent spin-polarized, which exhibits a tunable topological fermion density in the vicinity of the Kramers point and can be driven to the long-sought topological spin transport regime. The observed topological nodal state is shown to be protected even up to 300 K. Our demonstration of room-temperature topological order and non-trivial spin-texture in stoichiometric Bi2Se3.Mx (Mx indicates surface doping or gating control) paves the way for future graphene-like studies of topological insulators, and applications of the observed spin-polarized edge channels in spintronic and computing technologies possibly at room temperature.

    AB - Helical Dirac fermions - charge carriers that behave as massless relativistic particles with an intrinsic angular momentum (spin) locked to its translational momentum - are proposed to be the key to realizing fundamentally new phenomena in condensed matter physics. Prominent examples include the anomalous quantization of magneto-electric coupling, half-fermion states that are their own antiparticle, and charge fractionalization in a Bose-Einstein condensate, all of which are not possible with conventional Dirac fermions of the graphene variety. Helical Dirac fermions have so far remained elusive owing to the lack of necessary spin-sensitive measurements and because such fermions are forbidden to exist in conventional materials harbouring relativistic electrons, such as graphene or bismuth. It has recently been proposed that helical Dirac fermions may exist at the edges of certain types of topologically ordered insulators - materials with a bulk insulating gap of spin-orbit origin and surface states protected against scattering by time-reversal symmetry - and that their peculiar properties may be accessed provided the insulator is tuned into the so-called topological transport regime. However, helical Dirac fermions have not been observed in existing topological insulators. Here we report the realization and characterization of a tunable topological insulator in a bismuth-based class of material by combining spin-imaging and momentum-resolved spectroscopies, bulk charge compensation, Hall transport measurements and surface quantum control. Our results reveal a spin-momentum locked Dirac cone carrying a non-trivial Berry's phase that is nearly 100 per cent spin-polarized, which exhibits a tunable topological fermion density in the vicinity of the Kramers point and can be driven to the long-sought topological spin transport regime. The observed topological nodal state is shown to be protected even up to 300 K. Our demonstration of room-temperature topological order and non-trivial spin-texture in stoichiometric Bi2Se3.Mx (Mx indicates surface doping or gating control) paves the way for future graphene-like studies of topological insulators, and applications of the observed spin-polarized edge channels in spintronic and computing technologies possibly at room temperature.

    UR - http://www.scopus.com/inward/record.url?scp=69349084799&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=69349084799&partnerID=8YFLogxK

    U2 - 10.1038/nature08234

    DO - 10.1038/nature08234

    M3 - Article

    C2 - 19620959

    AN - SCOPUS:69349084799

    VL - 460

    SP - 1101

    EP - 1105

    JO - Nature Cell Biology

    JF - Nature Cell Biology

    SN - 1465-7392

    IS - 7259

    ER -